Edmund Maser is a Professor and Director of the Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School, Kiel, Germany. He is a member of two Excellence Clusters, “The Future Ocean” and “Inflammation at Interfaces”, and an Editorial Board Member of Toxicology, the Journal of Steroid Biochem. and Mol. Biology, and Toxics. His main area of research is reductive drug metabolism, where he established the field of pluripotent steroid oxidoreductases. These enzymes serve as steroid pre-receptor control and metabolize important carbonyl containing drugs, toxicants and carcinogens. Based on these studies, a variety of these carbonyl reducing enzymes gained importance in chemotherapy resistance, oxidative stress or protection against tobacco-smoke induced lung cancer. Importantly, Edmund Maser and his colleagues could identify the mechanism of steroid signaling in bacteria. More recently, he and his colleagues established the Blue mussel (M. edulis) as a bioindicator and biomonitoring system for explosive chemicals that leak from corroding sea-dumped munition. He has authored more than 225 original publications and reviews. His total number of citations is >5000 and current h-Index is 38.